The present invention relates to the field of the manufacture and use of cellulose filaments from renewable resources as well as products including such filaments.
Energy and resource conservation is an ever growing area of focus. Energy costs continue to rise and many material sources such as petroleum-based materials are under constant cost and availability concerns. One area in which this is particularly true is with disposable and semi-durable goods, especially in the area of consumer products used for personal, home and commercial applications.
Today's consumer daily routine often involves the use of products that are either single use products or products that are only used several times before being discarded. Non-limiting examples of such products include, but are not limited to, personal care absorbent articles, hygiene-related products, and cleaning products for home, business and commercial applications. Examples of personal care absorbent articles include, but are not limited to, diapers, diaper pants, training pants, feminine hygiene products, adult incontinence devices, wet and dry wipers, bandages and the like. Hygiene-related products include, but are not limited to, cleansing wipes, make-up and beauty wipes and pads. Cleaning products include, but are not limited to, household wipes and towels, paper towels, mop covers, etc.
Many of the foregoing and other products utilize petroleum-based materials such as polyolefin and other polymer-based filaments which are employed in the manufacture of fibrous nonwoven webs which are used to absorb and or dispense fluids. For example, many of the layers in personal care absorbent articles are made from polymer-based fibrous nonwovens.
An effort has been ongoing to make such filaments and nonwovens from sustainable resources and to move away from more petroleum-based products. One area has been in connection with the manufacture of such filaments and nonwovens from renewable raw materials which are cellulose-based. One well known method is referred to as the Lyocell process which is one of many examples of processes which require chemically-based solvents (N-methylmorpholine N-oxide) to dissolve the cellulose to permit it to be formed into a fiber. Once the fiber is formed other chemicals such as amine oxide is used to set the fiber after which the fibers have to be washed in water to remove the formation chemicals. Obviously this involves many processing steps, the use of additional chemicals that cost more money to use, extract and recycle and well as potential environmental issues concerning the use and disposal of the chemicals used in the process. It would therefore be desirable to have a more simplified process that would involve fewer steps, the use of fewer chemicals and therefore a lower cost in the context of manufacture. The present invention is directed to such an effort.